A large-scale parametric study of InP deposition on patterned substrates

Selective Area Epitaxy (SAE) is the process of locally depositing a semiconductor film on a substrate which has been patterned with an inert masking material such as SiO₂. During deposition by metalorganic chemical vapor deposition (MOCVD), the build up of precursors over the SiO₂ mask causes material to diffuse into the open areas leading to a growth rate increase. SAE is an important technique for electronic and photonic device fabrication, and for the monolithic integration of these devices. The present work is a single comprehensive study, which reports on the impact of all major MOCVD parameters to SAE indium phosphide films. The parameters include pressure, V/III pressure ratio, growth rate, temperature and mask geometry.     

Experimental studies and modeling of the oxidation of multiphase niobium-base alloys

A three-phase oxidation model has been developed for study the oxidation behavior of multiphase alloys. This model has been utilized to identify the oxidation behavior of three-phase Nb-base alloys and successfully predicted the critical value for the exclusive formation of CrNbO₄. It has shown that the exclusive formation of CrNbO₄ on the Nb-base alloys can be achieved by the volume fraction increasing and the particle size decreasing for NbCr₂ phase. Moreover, the barrier effect of Nb₅Si₃ phase on the diffusion of Cr in Nb-base alloys has also been deduced in this work.     

Decreasing energy consumption in address decoders by means of selective precharge schemes

This paper presents and evaluates three novel memory decoder designs which reduce energy consumption and delay by using selective precharging. These three designs, the AND-NOR, Sense-Amp, and the AND decoder, range in selectivity and select-line swing; these schemes charge and discharge fewer select-lines. This in turn consumes less energy than nonselective address decoders which charge and discharge all select-lines each cycle. These three decoding schemes are comprehensively simulated and compared to the conventional nonselective NOR decoder using 65 nm CMOS technology. Energy, delay, and area calculations are provided for all four 4-to-16 decoders under analysis. The most selective AND decoder performs best and dissipates between 61% and 99% less (73% less on average) and the selective Sense-Amp decoder performs only slightly worse by dissipating between 58% and 75% less (66% less on average) energy than dissipated by the NOR decoder. The AND-NOR decoder dissipates between 15% less and 20% more (6% more on average) energy than dissipated by the NOR decoder. In addition, the AND decoder is 7.5% and the Sense-Amp decoder is 5.0% faster than the NOR decoder, however, the AND-NOR decoder is 1.7% slower than the NOR decoder.     

High selectivity (SiN/SiO2) etching using an organic solution containing anhydrous HF

An etching process with high selectivity for SiN relative to SiO₂ at a low temperature is required for an etching process in LSI process. We achieved SiN film etching with high selectivity using an organic solvent (ethylene glycol dimethyl ether) containing anhydrous hydrogen fluoride. Selectivity as high as 15 was obtained at 80 °C. It was found that anhydrous HF effectively induces high selectivity for SiN relative to SiO₂. SiN film etching with high selectivity performed at low temperature for a single wafer process can be readily applied to future node technology devices.     

纳米光催化材料在空调领域中的应用

简要介绍了纳米光催化材料光 解室内空气中VOC（挥 有机化合物）的原理及国内外在此领域的研究应用情况，特别是日本在空气净化器中的应用，认为近期应加强理论研究，除开发家用空气净化器外，还应重视该技术在集中空调领域中的应用。     

Alkali deactivation of high-dust SCR catalysts used for NOx reduction exposed to flue gas from 100 MW-scale biofuel and peat fired boilers: Influence of flue gas composition

Deactivation of vanadium–titanium deNO_x SCR (selective catalytic reduction) catalysts in high-dust position have been investigated in three 100 MW-scale boilers during biofuel and peat combustion. The deactivation of the catalyst samples has been correlated to the corresponding flue gas composition in the boilers. Too investigate the effect on catalyst deactivation a sulphate-containing additive was sprayed into one of the furnaces. Increased alkali content on the SCR catalyst samples decreased the catalytic deNO_x activity. The study has shown a linear correlation between exposure time in the boilers and alkali concentration (mainly potassium) on the samples. The results imply that mainly alkali in ultra fine particles (<100 nm) in the flue gas increased the alkali accumulation on the catalyst samples. Low correlation was found between particles larger than 100 nm and the catalyst deactivation. It was not possible to decrease the deactivation of the catalyst samples by the sulphate-containing additive. Although the additive had an effect in sulphating potassium chloride to potassium sulphate, it did not decrease the amount of potassium in ultra fine particles or the deactivation of the catalyst samples.     

基于Chebyshev混沌扩谱序列的MC-CDMA系统的峰均功率比研究

峰均功率比(PAPR)是多载波码分多址 (MC-CDMA)系统的一个重要指标, OFDM多载波调制技术虽然可以提高MC-CDMA系统的数据传输率和抗干扰能力, 但是在系统的峰均功率比方面则存在着亟待解决的问题。本文利用Chebyshev混沌扩谱序列的伪随机、非周期、数量大和良好的相关特性,作为MC-CDMA系统上行信道的扩谱序列,以改善输出信号的峰均功率比。分析和仿真结果表明在保持较低多址接入干扰的同时,还可以大大降低发射信号的峰均功率比。     

Selective Laser Sintering of PEEK

Polyetheretherketone (PEEK) is a good choice especially for manufacturing medical instruments or implants. These parts are typically produced by conventional manufacturing methods, like injection moulding. Selective Laser Sintering (SLS) could offer more flexibility. It enables the direct manufacturing of products with complex geometries. Although SLS of polymers like polyamide or polystyrene is a standard industrial process already, laser sintering of PEEK remains a challenge.This article will show for SLS of PEEK the necessary adaptations in systems technology and material modifications and discuss a step-by-step process implementation. Process boundaries are shown concerning temperature and energy input. The high influence of porosity, which could be varied from zero to 15%, on mechanical properties is shown.     

Preparation and properties of V2O5 thin films for energy-efficient selective-surface applications

Thin V₂O₅ films have been prepared by thermal evaporation onto glass substrates at a pressure of about 1.99×10⁻³ Pa. The temperature dependence of electrical measurements exhibits an anomaly in resistivity at a temperature around 329 K. Temperature co-efficient of resistance (TCR) studies show positive values, so indicating semi-metallic behaviour up to a temperature of 363 K and the negative thereafter so indicating semi-conducting behaviour. Thickness-dependent resistivity measurement follows the Fuchs-Sordheimer size-effect theory. X-ray diffraction studies show that the material is amorphous. Optical studies show the material is highly transparent both in the visible and infrared regions. The integrated value of T_lum and T_sol is high, so indicating that the material is a potential candidate for selective surface applications.     

选择性分步溶解法研究碳酸锰矿物成分初探

在对４种碳酸盐纯矿物进行大量化学实验的基础上，以花垣锰矿南段试样为例，用选择性分步溶解的方法，研究了其碳酸锰矿物成分、种属及组分含量，结果与电子探针分析结果基本吻合，证实了该方法的可行性，从而为研究碳酸锰矿物成分找到了一种简单、经济、可行的新方法。